activemq-artemis/docs/user-manual/copied-message-properties.adoc

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ARTEMIS-4383 migrate user docs to AsciiDoc Markdown, which is currently used for user-facing documentation, is good for a lot of things. However, it's not great for the kind of complex documentation we have and our need to produce both multi-page HTML and single-page PDF output via Maven. Markdown lacks features which would make the documentation easier to read, easier to navigate, and just look better overall. The current tool-chain uses honkit and a tool called Calibre. Honkit is written in TypeScript and is installed via NPM. Calibre is a native tool so it must be installed via an OS-specific package manager. All this complexity makes building, releasing, uploading, etc. a pain. AsciiDoc is relatively simple like Markdown, but it has more features for presentation and navigation not to mention Java-based Maven tooling to generate both HTML and PDF. Migrating will improve both the appearance of the documentation as well as the processes to generate and upload it. This commit contains the following changes: - Convert all the Markdown for the User Manual, Migration Guide, and Hacking guide to AsciiDoc via kramdown [1]. - Update the `artemis-website` build to use AsciiDoctor Maven tooling. - Update `RELEASING.md` with simplified instructions. - Update Hacking Guide with simplified instructions. - Use AsciiDoc link syntax in Artemis Maven doc plugin. - Drop EPUB & MOBI docs for User Manual as well as PDF for the Hacking Guide. All docs will be HTML only except for the User Manual which will have PDF. - Move all docs up out of their respective "en" directory. This was a hold-over from when we had docs in different languages. - Migration & Hacking Guides are now single-page HTML since they are relatively short. - Refactor README.md to simplify and remove redundant content. Benefits of the change: - Much simplified tooling. No more NPM packages or native tools. - Auto-generated table of contents for every chapter. - Auto-generated anchor links for every sub-section. - Overall more appealing presentation. - All docs will use the ActiveMQ favicon. - No more manual line-wrapping! AsciiDoc recommends one sentence per line and paragraphs are separated by a blank line. - AsciiDoctor plugins for IDEA are quite good. - Resulting HTML is less than *half* of the previous size. All previous links/bookmarks should continue to work. [1] https://github.com/asciidoctor/kramdown-asciidoc
2023-07-27 23:45:17 -04:00
= Properties for Copied Messages
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There are several operations within the broker that result in copying a message.
These include:
* Diverting a message from one address to another.
* Moving an expired message from a queue to the configured `expiry-address`
* Moving a message which has exceeded its `max-delivery-attempts` from a queue to the configured `dead-letter-address`
* Using the management API to administratively move messages from one queue to another
When this happens the body and properties of the original message are copied to a new message.
However, the copying process removes some potentially important pieces of data so those are preserved in the following special message properties:
_AMQ_ORIG_ADDRESS::
a String property containing the _original address_ of the message
_AMQ_ORIG_QUEUE::
a String property containing the _original queue_ of the message
_AMQ_ORIG_MESSAGE_ID::
a String property containing the _original message ID_ of the message
It's possible for the aforementioned operations to be combined.
For example, a message may be diverted from one address to another where it lands in a queue and a consumer tries & fails to consume it such that the message is then sent to a dead-letter address.
Or a message may be administratively moved from one queue to another where it then expires.
In cases like these the `ORIG` properties will contain the information from the _last_ (i.e. most recent) operation.